Multi-needle injection device

Abstract

A medical device and a method of treating stress urinary incontinence are provided. The device includes a cannula with a plurality of apertures. A plurality of needles is disposed within a lumen of the cannula. A handle includes a housing and a shifter mechanism to translate the plurality of needles from a first position in which the needles are disposed within the lumen of the cannula, to a second position in which a distal portion of each needle extends out of the lumen through respective apertures. The handle also includes a slot including a transversal track defining a potential range of rotational motion of the shifter mechanism with respect to the housing, and a plurality of longitudinal tracks defining a potential range of translational motion of the shifter mechanism with respect to the housing. The shifter mechanism may also rotate the cannula with respect to the handle.

The invention claimed is: 
     
       1. A medical device comprising:
 an elongate cannula comprising:
 a distal end portion; 
 a proximal end portion; 
 a lumen defined therethrough; and 
 a plurality of apertures disposed through the distal end portion to provide communication with the lumen; 
 
 a plurality of injection needles disposed within the lumen, each comprising:
 a distal portion disposed in alignment with the plurality of apertures; and 
 a proximal end portion; 
 
 a handle fixed with respect to the cannula, the handle comprising:
 a housing configured to enclose a fluid volume; 
 a shifter mechanism coupled to the proximal end portion of the cannula and the proximal end portion of each of the plurality of needles, the shifter mechanism translatable with respect to the housing to translate the plurality of needles from a first position to a second position, the shifter mechanism rotatable with respect to the handle to rotate the cannula with respect to the handle; 
 a slot defined in the housing configured to receive a portion of the shifter mechanism therethrough, the slot comprising a transversal track and a plurality of longitudinal tracks, wherein the transversal track defines a potential range of rotational motion of the shifter mechanism with respect to the housing, and each longitudinal track defines a potential range of translational motion of the shifter mechanism with respect to the housing between the first and second positions; and 
 a conduit providing fluid communication between the fluid volume and the cannula; 
 
 wherein in the first position the distal portion of each of the plurality of needles is disposed within the lumen of the cannula; and 
 wherein in the second position the distal portion of each of the plurality of needles extends out of the lumen through respective apertures. 
 
     
     
       2. The medical device of  claim 1 , wherein the cannula further comprises a plurality of visually perceptible indicators configured to provide an indication of depth of insertion of the cannula within a patient. 
     
     
       3. The medical device of  claim 1 , wherein an outer circumferential surface of the distal end portion of the cannula defines an upper portion, a right side portion, a bottom portion, and a left side portion each substantially equally spaced from their respective neighboring portion around the circumferential surface of the cannula. 
     
     
       4. The medical device of  claim 3 , wherein
 a first of the plurality of apertures is disposed on the right side portion; 
 a second of the plurality of apertures is disposed on the bottom portion; and 
 a third of the plurality of apertures is disposed on the left side portion. 
 
     
     
       5. The medical device of  claim 3 , wherein the device is configured to be inserted into the patient's urethra with the upper portion of the cannula facing upwardly when the patient is oriented in a lithotomy position. 
     
     
       6. The medical device of  claim 1 , wherein the plurality of needles are configured to extend from the distal portion of the cannula multiple times while the device is inserted into a patient. 
     
     
       7. The medical device of  claim 1 , wherein the housing is configured to enclose a syringe enclosing the fluid volume. 
     
     
       8. The medical device of  claim 7 , the handle further comprising:
 a syringe actuation mechanism comprising:
 a thumbwheel; 
 a first tubular portion affixed to the thumbwheel; and 
 a second tubular portion configured to engage the first tubular portion and to partially receive the syringe. 
 
 
     
     
       9. The medical device of  claim 8 , wherein rotation of the thumbwheel produces a translational motion of the second tubular portion towards the proximal end of the housing, urging expulsion of the fluid volume from the syringe and out of the needles. 
     
     
       10. The medical device of  claim 1 , wherein the plurality of needles are configured to extent linearly about 7 mm from their respective aperture, and each needle exits their respective aperture at about a 40 degree angle with respect to a longitudinal axis of the cannula. 
     
     
       11. A method for treating stress urinary incontinence, comprising:
 providing a device with an elongate cannula with a plurality of apertures disposed upon a distal end thereof, a plurality of needles that each extend through a lumen in the cannula and selectively extend from each of the plurality of apertures, a handle manipulable to urge the plurality of needles to extend outward from the apertures, and to rotate the cannula and the needles with respect to the handle; 
 inserting the device into the patient in a first position; 
 manipulating the handle to extend the plurality of needles through the apertures; 
 expelling fluid from the plurality of needles; 
 retracting the plurality of needles into the cannula; 
 manipulating the handle to rotate the cannula and the needles into a second position within the patient; and 
 extending the plurality of needles through the apertures and expelling additional fluid from the plurality of needles. 
 
     
     
       12. The method of  claim 11 , further comprising:
 again retracting the plurality of needles into the cannula; 
 manipulating the handle to rotate the cannula and the needles into a third position within the patient; and 
 again extending the plurality of needles through the apertures and expelling additional fluid from the plurality of needles. 
 
     
     
       13. The method of  claim 11 , wherein:
 a first of the plurality of apertures is disposed on the right side portion of the distal end of the cannula; 
 a second of the plurality of apertures is disposed on the bottom portion of the distal end of the cannula; and 
 a third of the plurality of apertures is disposed on the left side portion of the distal end of the cannula. 
 
     
     
       14. The method of  claim 13 , wherein the cannula is configured such that no apertures are disposed upon an upper portion of the distal end of the cannula, and when the device is inserted in the first position the device is inserted into the patient's urethra with the upper portion of the distal end of the cannula facing upwardly when the patient is oriented in a lithotomy position. 
     
     
       15. The method of  claim 11 , wherein the device is configured to simultaneously inject fluid into various portions of tissue coaxially surrounding the urethra when in each of the first, second, and third positions, but avoid injecting into vessels and nerve bundles disposed proximate the urethra. 
     
     
       16. The method of  claim 11 , wherein the device further comprises a plurality of visually perceptible indicators configured to provide an indication of depth of insertion of the cannula within the patient, and further comprising the step of visually monitoring the depth of insertion of the cannula within the patient by observation of the plurality of visually perceptible indicators. 
     
     
       17. The method of  claim 11 , wherein the plurality of needles are configured to extend through a submucosa layer and into a muscle tissue coaxially surrounding a urethra when extended through the plurality of apertures. 
     
     
       18. The method of  claim 11 , wherein the fluid is a therapeutic agent. 
     
     
       19. A medical device comprising:
 an elongate cannula comprising:
 a distal end portion, wherein an outer circumferential surface of the distal end portion defines an upper portion, a right side portion, a bottom portion, and a left side portion each substantially equally spaced from their respective neighboring portion around the circumferential surface of the cannula; 
 a proximal end portion; 
 a lumen defined therethrough; and 
 a plurality of apertures disposed through the distal end portion to provide communication with the lumen, wherein a first of the plurality of apertures is disposed on the right side portion; a second of the plurality of apertures is disposed on the bottom portion; and a third of the plurality of apertures is disposed on the left side portion; 
 
 a plurality of injection needles disposed within the lumen, each comprising:
 a distal portion disposed in alignment with the plurality of apertures; and 
 a proximal end portion; 
 
 a handle fixed with respect to the cannula, the handle comprising:
 a housing configured to enclose syringe enclosing a fluid volume; 
 a shifter mechanism coupled to the proximal end portion of the cannula and the proximal end portion of each of the plurality of needles, the shifter mechanism translatable with respect to the housing to translate the plurality of needles from a first position to a second position, the shifter mechanism rotatable with respect to the handle to rotate the cannula with respect to the handle; 
 a slot defined in the housing configured to receive a portion of the shifter mechanism therethrough, the slot comprising a transversal track and a plurality of longitudinal tracks, wherein the transversal track defines a potential range of rotational motion of the shifter mechanism with respect to the housing, and each longitudinal track defines a potential range of translational motion of the shifter mechanism with respect to the housing between the first and second positions; 
 a conduit providing fluid communication between the syringe and the cannula; and 
 a syringe actuation mechanism comprising:
 a thumbwheel; 
 a first tubular portion affixed to the thumbwheel; and 
 a second tubular portion configured to engage the first tubular portion and to partially receive the syringe; 
 
 
 wherein in the first position the distal portion of each of the plurality of needles is disposed within the lumen of the cannula; 
 wherein in the second position the distal portion of each of the plurality of needles extends out of the lumen through respective apertures; and 
 wherein rotation of the thumbwheel produces a translational motion of the second tubular portion towards the proximal end of the housing, urging expulsion of the fluid volume from the syringe and out of the needles. 
 
     
     
       20. The medical device of  claim 19 , wherein the cannula further comprises a plurality of visually perceptible indicators configured to provide an indication of depth of insertion of the cannula within a patient.